Tuesday, August 22, 2006

Marmosets give lives to show how fatherhood may change brain

Marmoset monkey fathers who carry their infants show physical changes in a part of their brains associated with goal-directed behaviour and planning, a study found.

Monkey fathers with recent offspring had changes in their pre-frontal cortexes including increased numbers of the tiny features called dendritic spines, said Princeton University professor Elizabeth Gould in this week’s issue of Nature Neuroscience. The finding was the latest in a series to show that the brains of adult mammals can change as a result of physical and even social stimuli.

Further study will be needed to determine whether the changes actually make the brains more efficient. That area of the brain in marmosets is associated with short-term memory, goal-directed behaviour and planning, Gould said. In humans, that part of the brain also affects moral reasoning and possibly personality and emotions, she said.

The act of caring for the young might be what causes the brains to change, Kozorovitskiy said. Newborns in the study were carried by fathers more than 70% of the time in the first month, the study said.

“Marmosets are unusual among mammals as the fathers care extensively for offspring”. Gould and her researchers previously found brain changes in other adult mammals, such as rats that grew new neurons when they became dominant in a small community, Princeton Weekly Bulletin reported last year.

Twelve of the eight-inch-tall monkeys were sedated and killed to complete the study.